1. Field
The present disclosure relates to anti-C1q antibodies and methods of using them.
2. Description of Related Art
Excessive complement activation has been associated with a range of disease conditions, including numerous inflammatory and autoimmune diseases. More recently, the complement system has also been shown to contribute to neurodegenerative disease pathology. Specifically, complement factors, such as C1q, were shown to be expressed in neuronal synapses and to mark these synapses for elimination. See, e.g., U.S. Patent Publication Nos. 2012/0195880 and 2012/328601. While selective synapse loss is an essential aspect of normal brain development (“synaptic pruning”), excessive synapse loss, especially in a mature or aging brain, results in neurodegeneration and cognitive decline. Elevated synaptic complement expression was found to contribute to synaptic loss in normal aging and in neurodegenerative disease progression. Conversely, lowering neuronal complement expression was found to be neuroprotective. Based on these findings, neutralizing the activity of complement factors such as C1q is regarded as a promising therapeutic strategy to prevent synapse loss and to slow neurodegenerative disease progression as well as cognitive decline in normal aging.
Neurodegenerative diseases involving synapse loss and considered to be amenable to treatments aiming at the neutralization of complement factors such as C1q include Alzheimer's disease, amyotrophic lateral sclerosis, multiple sclerosis, glaucoma, myotonic dystrophy, Down syndrome, Parkinson's disease, Huntington's disease, and the like.
Only a limited number of complement neutralizing antibodies are known to date (see, e.g., Klos A. et al., Mol Immunol. 2009, 46(14), 2753-2766; Carroll S. & Georgiou G., Immunobiology 2013, 218(8), 1041-1048; Tuzun et al., J. Neuroimmunol. 2007, 182, 167-176; Nelson et al., J. Clin. Invest. 2006, 116:2892-2900; Heinz et al., J. Immunol. 1984, 133, 400-404; Jiang et al., J. Immunol. 1991, 146, 2324-2330; Trinder et al., Scand. J. Immunol. 1999, 50, 635-641; Hwang et al., Mol. Immunol. 2008, 45, 2570-2580). Only the C5 neutralizing antibody Eculizumab, an inhibitor of the terminal complement activation pathway, has obtained regulatory approval to date; Eculizumab is marketed for the treatment of paroxysmal nocturnal hemoglobinuria (PNH; Hillmen et al., N Engl J Med. 2006, 355(12):1233-43).
Thus, there is a need to develop further antibodies that specifically bind to and neutralize biological activities of complement factors such as C1q.
All references cited herein, including patent applications and publications, are hereby incorporated by reference in their entirety.